Rates of Reaction

Experiment 1              Investigating the Effect of Temperature on Reaction Rate

Aim:
I want to investigate how temperature effects the reaction rate.

Equipment:
A conical flask, beaker, measuring cylinder, stopwatch, black cross on paper, water bath, thermometer, 0.l mol L-1 hydrochloric acid (HCl).

Method:
1. Put the 'X' paper on the bench mat, and put the conical flask on top of the paper.
2. Measure 50 mL of sodium thiosulfate solution and put it into the beaker.
3. Record the temperature of the sodium thiosulfate.
4. Measure 5 mL of HCl and pour this into the conical flask.
5. Pour the sodium thiosulfate into the conical flask, start the stopwatch and swirl the flask. Time how long it takes for the cross to disapear when viewed from above (i.e. look down the mouth of the conical flask)
6. Wash out the flask thoroughly.
7. Repeat the experiment, using a water bath to heat the sodium thiosulfate to 30 degrees, then 40 degrees and finally 50 degrees. Keep the volume of acid the same each time.

Results:
Non Heated
sodium thiosulfate - 12 degrees
HCl - 31.41 seconds

Heated(30 degrees)
sodium thiosulfate - 30 degrees
HCl - 9.60 seconds

Heated(40 degrees)
sodium thiosulfate - 40 degrees
HCl - 13.10 seconds

Heated(50 degrees)
sodium thiosulfate - 50 degrees
HCl - 3.46 seconds


Experiment 2                  Investigating the Effect of Concentration on Reaction Rate

Aim:
I want to investigate how concentration effects the reaction rate.

Equipment:
A conical flask, measuring cylinder, stopwatch, black cross on paper, 0.2 mol L-1 sodium thiosulfate, 1.0 mol L-1 hydrochloric acid.

Method:
1. Put the 'X' paper on the bench mat, and put the conical flask on top of the paper.
2. Measure 10 mL of sodium thiosulfate solution and put it into the conical flask.
3. Measure 40 mL of water and put it into the conical flask. Swirl the flask to mix the contents.
4. Measure 5 mL of acid. Pour the acid into the flask, start the stopwatch, and swirl the flask. Time how long it takes for the cross to disappear.
5. Wash out the flask throughly. Repeat the experiment using the other volumes of the sodium thiosulfate and water in the table on the right. Keep the volume of acid the same each time.

Results:
10 mL of sodium thiosulfate/40 mL of water
4 minutes, 43 seconds
20 mL of sodium thiosulfate/30 mL of water
2 minutes
30 mL of sodium thiosulfate/20 mL of water
54.63 seconds
40 mL sodium thiosulfate/10 mL of water
44.22 seconds
50 mLof sodium thiosulfate/0 mL of water
33.62 seconds


Experiment 3                  Observing the Effect of Surface Area on Reaction Rate

Aim:
I want to observe the effects of surface area on reaction rate.

Equipment:
boiling tube, calcium carbonate chips and powder, hydrochloric acid, measuring cylinder, spatula

Method:
1. Measuring 2 mL of hydrochloric acid and pour this into your boiling tube.
2. Holding your boiling tube over a sink or heatproof mat, add a pea-sized amount of calcium carbonate powder to your boiling tube.
3. Repeat the experiment, but this time use a chip of calcium carbonate that is roughly the same size as the spatula of power you used previously.

Observations:
When I added the powder, it fizzed up.
When I used chips, it bubbled up.


Experiment 4                        Catalysts

Aim:
I want to observe the effects of a copper catalysts on the reaction between zinc and sulfuric acid.

Method:
1. Add roughly the same mass of zinc to test tubes 1 and 3
2. Add roughly the same mass of copper to test tubes 2 and 3
3. Add 5 mL of dilute sulfuric acid to test tube 1
4. Add 5 mL of acid to test tube 2
5. Add 5 mL of acid to test tube 3

Observations:
Test tube 1 - it fizzed up
Test tube 2 - it bubbled up
Test tube 3 - nothing much happened